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Background: Tumor necrosis factor (TNF)-α inhibitor has been shown to affect the periodontal condition of patients with rheumatoid arthritis (RA). The aim of the present study is to assess the effect of a fully humanized anti-TNF-α monoclonal antibody, adalimumab (ADA), on the periodontal condition of patients with RA and to compare serum protein profiles before and after ADA therapy., Methods: The study participants consisted of 20 patients with RA treated with ADA. Clinical periodontal and rheumatologic parameters and serum cytokine levels were evaluated at baseline and 3 months later. Serum protein spot volume was examined with two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis. Proteins with significant difference in abundance before and after ADA therapy were found and identified using mass spectrometry and protein databases., Results: The patients showed a significant decrease in gingival index (P = 0.002), bleeding on probing (P = 0.003), probing depth (P = 0.002), disease activity score including 28 joints using C-reactive protein (P <0.001), and serum levels of TNF-α (P <0.001) and interleukin-6 (P <0.001) after ADA medication, although plaque levels were comparable. Among a total of 495 protein spots obtained, nine spots were significantly decreased in abundance at reassessment, corresponding to complement factor H, phospholipase D, serum amyloid A, complement component 4, and α-1-acid glycoprotein (P <0.01)., Conclusion: These results suggest a beneficial effect of ADA therapy on the periodontal condition of patients with RA, which might be related to differences in serum protein profiles before and after ADA therapy.

Activity-guided fractionation for complement inhibitors led to the isolation of 23 known compounds from Houttuynia cordata Thunb. Seven flavonoids, two alkaloids, one coumarin and two phenols showed anti-complementary activity. Preliminary inhibitory mechanism of four flavonoids, including quercitrin, afzelin, isoquercitrin and quercetin in the complement activation cascade were examined for the first time. The results indicated that the target components of flavonols are different from those of flavonosides, and the glycoside moieties may be necessary to block C3 and C4 components.

Background: The role of the complement system in antibody-mediated rejection has been investigated in relation to circulating complement interacting with renal microvascular endothelium, resulting in the formation of peritubular capillary C4d. However, the possible importance of local complement synthesis is less clear. The aim of this study was to determine whether human vascular endothelium could produce C4 in response to stimulation in vitro., Methods: Human microvascular endothelial cells and glomerular endothelial cells were stimulated with endotoxins, cytokines, and human leukocyte antigen-specific antibodies. Synthesis of complement was investigated using western blotting and indirect immunofluorescence. De novo C4 synthesis was confirmed by using C4 small interfering RNA., Results: Glomerular and microvascular endothelium, both produce C3 and C4 complement protein. Complement synthesis was stimulant-specific-C3 was produced mainly after stimulation with lipopolysaccharide whereas C4 synthesis occurred on treatment with gamma interferon. Culture with human leukocyte antigen-specific antibodies resulted in a significant increase of C4 protein synthesis by both cell lines., Conclusions: We have shown for the first time that human microvascular endothelium can be stimulated to synthesize C4 in vitro. The implications of this for clinical transplantation, especially in the context of antibody-mediated rejection, its histological interpretation and as a potential target for therapy would have to be determined by further studies.

In this review we address the main cutaneous manifestations and diseases associated with deficiencies in components of the complement system. The first part is devoted to hereditary angioedema, in which acute, sometimes life-threatening recurrent attacks of acute swelling, usually associated with gastrointestinal symptoms, occur. It is related to a structural or functional deficiency of C1 esterase inhibitor. Patients usually have lowered C4 levels, and diagnosis relies on determination of antigenic and/or functional C1 inhibitor level. The second part focuses on lupus erythematosus, as deficiencies in early components of the complement system, such as C1q, C1r, C1s, C2 or C4, are the strongest known disease susceptibility genes for the development of human systemic lupus erythematosus. Severe infections early in life and marked photosensitivity in a patient with lupus erythematosus are clues to an underlying complement deficiency. The genetic background and the clinical associations of the different components of the complement system will be detailed.

Our investigation was carried out on an assumption that end results among patients radically-treated for colorectal cancer might be improved by use of enteroabsorption. The study group included 17, controls--13 patients with diagnostically verified stage I-III tumors. Mixed sorbent (microcellulose + polysorb) (6g) was administered, once a week, on the average of 20 days after operation. Immunological vigor was assayed 3 weeks after surgery: immunoglobulin levels--by turbodimetric method, cellular profile of lymphocytes--monoclonal antibodies to cell markers CD3, CD4, CD8, CD16 and CD22. As a result of adjuvant treatment CD22 (B-lymphocytes) concentration increased significantly--from 17.70 to 21.66 (22%), while CD16 (innate killers) both in absolute numbers (19%) and by percentage points (9%). Circulating immunocomplex levels in the sorbent-treatment group were significantly lower (37.44 ths units) than in control (48 ths units) (average 28%). No relapse or metastases were reported in either group.

Scleroderma and eosinophilia often occur together, though the pathogenesis is unclear. We investigated the effect of olopatadine hydrochloride in a series of cases of limited scleroderma (LS). Ten patients with LS and positive eosinophil counts (LSE) were enrolled (average age, 85 years; six men and four women). Serum concentrations of the anti-Scl-70 antibody were positive. Olopatadine hydrochloride was prescribed at 10 mg/day for 3 weeks. Serum concentrations of the anti-Scl-70 antibody significantly decreased, but changes in eosinophil numbers and percentages in peripheral blood were not significant. Factor analysis suggested a correlation between serum concentrations of the anti-Scl-70 antibody and complement C4. Olopatadine could be effective in reducing anti-Scl-70 antibodies in the elderly with LSE.

Background and Objective: There is contradictory evidence as to whether the pleiotropic effects of statins improve morbidity/mortality rates in coronary artery bypass grafting with extracorporeal circulation, as they reduce the protein plasma levels in the acute phase., Patients and Method: This randomized prospective study included 44 patients undergoing elective coronary artery bypass grafting with extracorporeal circulation who were allocated to one of 2 groups: group A (n = 22), patients taking simvastatin, and group B, control (n = 22). The plasma levels of interleukin-6, complement 4 and C-reactive protein were determined., Results: No significant differences were noted between the 2 groups with respect to the acute-phase protein levels, or the postoperative complications. In both groups, compared with the initial levels, interleukin-6 levels peaked at 6 h after surgery and C-reactive protein at 48 h. Complement 4 levels decreased from the start of the cardiopulmonary bypass and returned progressively toward the baseline value at 48 h after surgery., Conclusions: Simvastatin in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass produces no significant differences in the levels of acute-phase protein.

Objective: The purpose of this study was to assess the effect of preoperative dexamethasone (DEX) on the occurrence of postoperative atrial fibrillation (AF)., Design: Prospective, randomized, double-blind, placebo-controlled clinical trial., Setting: Tertiary referral center., Participants: Seventy-eight adult patients undergoing combined valve and coronary artery bypass graft (CABG) surgery were randomized to receive either DEX or placebo., Interventions: The DEX group received dexamethasone, 0.6 mg/kg, after induction of anesthesia, and the placebo group received an equal volume of normal saline. Interleukin (IL)-6, -8, and -10; tumor necrosis factor alpha; and endothelin (ET)-1 were measured preoperatively and on postoperative days (POD) 1, 2, and 3. Complement (C-4) and C-reactive protein (CRP) were measured preoperatively and on POD 2. Exhaled nitric oxide (NO) was measured preoperatively, 15 minutes after aortic unclamping, and 1 hour after intensive care unit admission., Measurements and Main Results: No significant difference in the incidence of AF was found between the placebo (41%) and DEX groups (30%) (95% confidence interval [-11%, 34%); p = 0.31). DEX significantly reduced at least 1 postoperative level of IL-6, IL-8, IL-10, CRP, and exhaled NO. DEX did not affect ET-1 or C-4 levels. IL-10 on POD 3 was positively correlated with postoperative hospital length of stay (r = 0.30, p = 0.01). Increased levels of IL-8 and IL-10 on POD 1 were positively correlated with the intubation time (r = 0.31, p = 0.01; r = 0.30, p = 0.01, respectively). Conversely, C-4 on POD 2 was negatively correlated with the intubation time and intensive care unit length of stay (r = -0.32, p = 0.006; r = -0.30, p = 0.01, respectively)., Conclusions: DEX did not affect the incidence of AF in patients undergoing combined CABG and valve surgery. However, it did modulate the release of several inflammatory and acute-phase response mediators that are associated with adverse outcomes.

Objective: To evaluate the effect of conjugated equine estrogens (CEE) plus medroxyprogesterone acetate (MPA) and raloxifene on serum levels of complement C3 and C4 fractions in postmenopausal women., Patients and Method: Twenty healthy postmenopausal women were studied. In all weight, height and body mass index (BMI) were documented. FSH and estradiol levels were measured. They were randomly divided into two groups, according to the treatment they received: group I, CEE 0.625 mg/day plus MPA 2.5 mg/day (n = 7); group II, raloxifene 60 mg/day (n = 13), both treatments were continuous. Serum levels of C3 and C4 complement fractions were measured by immunonephelometry at baseline and six months after start of treatment. Differences among groups of baseline and final C3 and C4 levels were measured with Student's t test for independent and paired samples, respectively., Results: There were no differences among groups in age, weight, height and body mass index, neither in C3 and C4 levels among baseline and final levels when comparing each group separately., Conclusions: Complement may not intervene significantly in the atherosclerotic inflammatory process in women receiving CEE plus MPA or raloxifene.

Background: The virilizing effects of danazol, stanozolol, and methyltestosterone significantly restrict the usefulness of these agents in the treatment of children with hereditary angioedema (HAE). Oxandrolone is a synthetic anabolic steroid with limited virilizing effects that has been used in a variety of pediatric conditions and has an acceptable safety profile., Objective: To report the effective use of oxandrolone in a 6-year-old boy with recurrent, life-threatening episodes of angioedema., Methods: Oxandrolone was administered at a dose of 0.1 mg/kg per day. Symptoms and laboratory findings were evaluated by parental report and laboratory analysis of serum C1 esterase inhibitor and C4 levels, respectively., Results: Oxandrolone therapy resulted in a marked reduction in clinical episodes and normalization of serum complement levels; cessation of oxandrolone therapy resulted in recurrence of symptoms and decreased complement levels. However, early signs of virilization were noted., Conclusions: Oxandrolone treatment was associated with significant clinical and laboratory evidence of a therapeutic effect in a prepuberal boy with HAE. It is imperative to treat HAE with the lowest dose of oxandrolone that controls life-threatening episodes of angioedema.

This paper discusses the application of factor analysis when used to compare selected blood parameter (a three-parameter smear, hematocrit, C3c, C4, IgG, IgA, IgM, CRP, fibrinogen and the level of factor XII) properties, just before, and after exposure to pressure changes, and 24-hours after the completion of decompression. To-date the most popular method of statistical analysis was based only on investigation of the significance of the separated individual parameters. This factor analysis that has not been applied previously in the analysis of such problems, enabled the neutral hierarchic evaluation of the significant parameter changes within their chosen range, and mutual relationships. It seems that the application of this method is purposeful and it can be an objective tool for evaluating the significance of changes in blood constituency induced by pressure.

In the Polish Navy, deep-water dives, performed for the needs of the maritime industry, are conducted using our own national technology and trimix as a breathing medium. In this paper are presented the results obtained during a short-time deep-water diving test using the principles of US Navy technology, combined with the use of diving equipment type AF-2 and heliox-type breathing mixture in the open circuit. In the performed examinations changes in clinical parameters were assessed viz.: blood morphology, hematocrit level, concentration of C3c, C4, IgG, IgA, IgM, CRP, concentration of fibrinogen and factor XII level, obtained 30 minutes prior to commencement, immediately after completion, and 24 hours after termination of the exposure. The results thus generated were subjected to a preliminary analysis by the description of trends observed. It was revealed that the diving technology employed did not generate substantial changes in the examined parameters of blood in divers, and the increase of neutrophils, blood platelets and fibrinogen concentration in the blood plasma immediately after diving is of temporary character, being a typical reaction observed during diving.

A simple test-system has been developed for the first time in order to detect the ability of effectors (lipoplexes) to activate the complement system in an antibody-independent manner to serve as acceptors of nascent C4b and to inhibit formation of the key enzyme of complement, C3-convertase. The effect of plasmid DNA (pCMV-SPORT-LacZ), negatively charged cardiolipin (CL), neutral phosphatidylcholine (PC) vesicles and their lipoplexes, on the complement system was studied using the method developed. It was revealed that PC vesicles did not affect the complement system, while CL vesicles manifested low activation. The influence of plasmid DNA and its lipoplex based on PC liposomes as well on the complement system was very low. PC/LacZ lipoplex (143 microg/ml) acted on the complement system like 5.36 microg/ml heat aggregated IgG (agg) (the level of no pathological ruptures), whereas CL/LacZ lipoplex (143 microg/ml) acted similar to 10.7 microg/ml IgG (agg). Thus, weak activation of the complement system with CL lipoplex, and even weaker for the PC lipoplex testified to the use of neutral and positively charged lipoplexes preferably in gene therapy protocols. The technique can also be used for testing the influence of injectable gene therapy vectors on the complement system.

In this study, the authors administered high dose (30 mg/kg body weight i.v.) methylprednisolone before cardiopulmonary bypass to observe the effects on complement, immunoglobulins and pulmonary neutrophil sequestration. Fifty patients undergoing valve replacements were included in this study. Patients were divided into two groups: group I (20 patients) served as control and did not receive methylprednisolone, group II (30 patients) received methylprednisolone. Blood samples for complements (C3c and C4) were taken, before cardiopulmonary bypass, at 5, 10 and 30 min intervals from the end of cardiopulmonary bypass, after reversal of heparin with protamine infusion, and after skin closure. Blood samples for immunoglobulins were taken before cardiopulmonary bypass, 30 min after onset of cardiopulmonary bypass and after skin closure. After onset of cardiopulmonary bypass, all C3c and C4 levels decreased in both groups. There was a significant decrease in C4 levels at end of cardiopulmonary bypass and after protamine infusion in group I compared with group II (P < 0.05). C3c levels in group I decreased significantly compared with group II after 30 min of cardiopulmonary bypass and after protamine infusion (P < 0.05). All immunoglobulin (IgG, IgM, IgA) levels were decreased in both groups, but the decrease in IgG was statistically significant after skin closure in group I compared with group II (P < 0.05). Pulmonary neutrophil sequestration was higher in the control group compared with the methyl-prednisolone group (P < 0.05). In conclusion, methylprednisolone administration before cardiopulmonary bypass may prevent the harmful effects of complement activation, immunoglobulin denaturation and neutrophil sequestration in the pulmonary capillary system.

Objective: To study prospectively the serum prolactin (PRL) concentrations among male patients with systemic lupus erythematosus (SLE) and their possible relationship to disease activity and manifestations., Methods: Serum PRL levels were measured by radioimmunoassay in 31 male patients with SLE and 31 age matched controls. Demographic, clinical, and laboratory features of the patients were obtained. Mean PRL levels from both groups were compared, and PRL from patients with SLE was correlated with variables of disease activity, including the SLE Disease Activity Index (SLEDAI), complement level, and anti-dsDNA titer. Thirteen patients were followed serially and changes in PRL levels in relation to fluctuation in disease activity were evaluated., Results: Mean PRL levels were higher in male patients with SLE than healthy controls; however, the difference did not reach statistical significance (230 vs 194 mIU/l; p = 0.06). Hyperprolactinemia was found in 4 patients (13%) and was not associated with particular clinical manifestations or autoantibodies. Considering all patients as a whole, PRL levels did not correlate with variables of disease activity and there was no difference in PRL between patients with active versus inactive disease. A subanalysis of the 4 hyperprolactinemic patients revealed a higher SLEDAI score than those with normal PRL (8.8 vs 3.7; p = 0.20); however, the difference was not statistically significant. Among the hyperprolactinemic patients, PRL levels did not correlate with SLEDAI score or anti-dsDNA titer. Prospective studies of PRL levels in 13 patients did not indicate a role of PRL in the monitoring of disease activity or predicting relapses., Conclusion: Hyperprolactinemia occurred in a small proportion of male patients with SLE and its significance remained unclear. Serum PRL level did not correlate with disease activity and was not a reliable marker for disease monitoring.

Stellate cells play an important role in the production and turnover of the normal extracellular matrix of the liver and are key effector cells in the hepatic fibrogenesis that occurs in response to liver injury. In the present study, we used a rat model of long term dietary iron supplementation to identify stellate cell genes that are expressed during chronic hepatic iron overload. Using a subtraction cloning strategy, we identified a rat isoform of the complement C4 protein gene whose expression was strongly induced in stellate cells after iron overload. Highly purified, cultured stellate cells synthesized the C4 precursor protein and released its subunits into the culture medium. The C4 protein secreted in vitro was biologically active in a C4-specific hemolytic assay. C4 mRNA expression was minimal in freshly isolated stellate cells and increased between days 3 and 7 of primary culture, coincident with the expression of smooth muscle alpha-actin (alpha-SMA), a marker of cellular activation. C4 expression was absent in strongly alpha-SMA-positive, passaged cells, but was induced by IFN-gamma, which simultaneously inhibited alpha-SMA expression. Our studies establish hepatic stellate cells as a previously unrecognized source of C4 and raise the possibility that complement protein expression by the cells plays a role in the hepatic injury response and in fibrogenesis. Our in vitro data point to the presence of two distinct stimulatory pathways for C4 expression in stellate cells that differ with regard to their sensitivity to IFN-gamma and their relationship to cellular activation.

Local production of complement within normal or diseased kidneys could be of importance during local inflammatory reactions. In the present study, we demonstrate that human MCs are able to synthesize the MHC class-III-encoded complement proteins factor B and C4 in vitro. This synthesis is strongly upregulated following stimulation with cytokine-containing supernatants of activated peripheral blood mononuclear cells. All primary cell lines tested so far are able to synthesize factor B and C4 after stimulation. To determine more specifically whether defined cytokines are able to enhance factor B and C4 complement production, MCs were stimulated with IL-1 alpha, IFN-gamma, and TNF-alpha. Factor B synthesis was increased in a dose-dependent fashion by IL-1 alpha, TNF-alpha, and IFN-gamma, whereas C4 synthesis was only upregulated by IFN-gamma. Furthermore, factor B synthesis was upregulated after stimulation with IFN-alpha, -beta, and -gamma and C4 synthesis only by IFN-gamma. The synthesis of factor B and C4 was inhibited by cycloheximide, suggesting de novo protein synthesis. The cytoplasmic localization of both components was shown by immunofluorescence studies. Northern and dot blot analysis revealed induction of factor B and C4 mRNA after stimulation with cytokines.

Major basic protein, the primary constituent of eosinophil granules, regulates the alternative and classical pathways of complement. Major basic protein and other eosinophil granule cationic proteins, which are important in mediating tissue damage in allergic disease, regulate the alternative pathway by interfering with C3b interaction with factor B to assemble an alternative pathway C3 convertase. In the present study, eosinophil peroxidase, eosinophil cationic protein and eosinophil-derived neurotoxin, as well as major basic protein, were examined for capacity to regulate the classical pathway. Eosinophil peroxidase, eosinophil cationic protein and major basic protein inhibited formation of cell-bound classical pathway C3 convertase (EAC1,4b,2a), causing 50% inhibition of complement-mediated lysis at about 0.19, 0.75 and 0.5 micrograms/10(7) cellular intermediates, respectively. Eosinophil-derived neurotoxin had no activity on this pathway of complement. The eosinophil granule proteins were examined for activity on the formation of the membrane attack complex. Major basic protein and eosinophil cationic protein had no activity on terminal lysis. In contrast, eosinophil peroxidase inhibited lysis of EAC1,4b,2a,3b,5b, but had only minimal activity on later events in complement lysis. These polycations were then examined to determine the site(s) at which they regulated the early classical pathway. Eosinophil granule polycationic proteins: (1) reduced the Zmax at all time points but had only minimal effect on the Tmax during the formation of the classical pathway C3 convertase (EAC1,4b,2a); (2) inhibited formation of EAC1,4b,2a proportional to C4 but independent of C2 concentration; (3) inhibited fluid phase formation of C1,4b,2a, as reflected by a decrease in C1-induced consumption of C2 over time; and (4) inhibited C1 activity over time without a direct effect on either C4 or C2. These observations suggest that polycations regulate the early classical pathway by interfering with C1 and may exert this activity in vivo.

A rapid and efficient procedure for purification from Vipera lebetina venom of a low molecular weight anticomplement protein is described. The procedure used gel filtration on Superose 12, followed by ion-exchange chromatography on a Mono Q column. The purified protein migrated on SDS-PAGE as a single band of about 25,000 Da under nonreducing conditions and as a band of 16,000 Da under reducing conditions. Its isoelectric point was estimated to be 7.6 +/- 0.1. The isolated Vipera lebetina protein was found to decrease the hemolytic activity in human serum measured by assays for classical pathway and alternative pathway activation. The loss of the complement activity could be ascribed, at least in part, to a proteolytic cleavage of the alpha chains of C3 and C4. This protein was also found to be without action on human blood coagulation and on purified fibrinogen and Factor B.

Thiol compounds have been investigated as inhibitors of the covalent binding reaction of human complement protein C4 using Sepharose-C1s as a combined activating and binding surface. o- and p-substituted aminothiophenols are equally effective inhibitors, whereas the m-substituted compound is a less potent inhibitor. The anti-hypertensive drug captopril is also shown to inhibit the covalent binding reaction. A comparison of the effects of these compounds on the covalent binding reaction of isolated C4A and C4B has been made. Results suggest that a Pro-to-Leu substitution in C4B is likely to account for the differences in inhibitory potency of C4B compared with C4A observed with the aromatic inhibitors.

The fourth component of human complement (C4) is encoded at two separate but closely linked loci within the MHC on the short arm of chromosome 6. Thus, there are two types of C4 protein in most individual and pooled normal human sera (NHS): C4A and C4B. Incubation of individual sera, pooled NHS, or purified heterogeneous C4 (C4A/C4B) with bacterial sialidase at 37 degrees C increased C-mediated hemolysis of antibody-sensitized sheep erythrocytes 1.54- to 1.93-fold. Comparative studies of Tmax of human C2, using asialo-C4 or buffer-treated C4 on EAC1gp and extrapolation to time 0 indicated a z value 4-fold higher with asialo-C4. This indicated that more hemolytically active C42 complexes are available with sialidase-treated C4 compared to untreated C4. There was no appreciable difference in the % 125I-C4 bound to EAC1gp (sialidase- or buffer-treated). Sera from two different blood donors with C4A3 phenotype (C4BQ0), two different donors with C4B1 phenotype (C4AQ0), and serum from an individual heterozygous deficient at both C4A3 and C4B1 regions (A3, AQ0; B1, BQ0) were investigated. The C4 allotypes, purified from these sera, were treated with sialidase; the C4A3 was enhanced in hemolytic assays by sialidase-treatment (1.52- to 2.3-fold), whereas the C4B1 allotype was not enhanced. Fluorometric determinations revealed that approximately the same percentage of sialic acid was released from sialidase-treated C4A3 and C4B1. Therefore, the increase in hemolytic titer observed after treatment of NHS or purified heterogeneous C4 with sialidase is a property of C4A3 but not a property of C4B1.

Since influenza increases the mortality of chronically ill patients we decided to study the effectiveness of influenza vaccination in hemodialysis (HD) patients. Nineteen HD patients aged from 20 to 60 years, on unrestricted diet and with no febrile episode, were studied. Blood samples were collected before the intramuscular injection of 0.5 mL multivalent influenza vaccine (Inflexal Berna) and every 2 weeks thereafter. At the end of 4th week a second vaccination was done and a dosage of 200 mg of zinc acetate (60 mg elemental zinc) was given daily to each patient for at least 4 weeks. Before vaccination the antibody titers to influenza virus ranged from 1:10 to 1:80 and after vaccination from 1:20 to 1:640. Four weeks after vaccination 6/19 (31.5%), 8/19 (42%), and 10/19 (52.5%) patients showed a fourfold or greater increase at serum antibody titers to antigens A/Singapore, A/Sichuan, and B/Beijing, respectively. The zinc supplementation after the second vaccination induced a similar increase of serum antibody titers to the A/Singapore but some even greater increase of the antibody titers to the A/Sichuan and B/Beijing. Serum immunoglobulins and complement components C3/C4 were not changed during this study. It is suggested that about 50% of uremic patients respond to the influenza vaccination and that zinc treatment does not increase this responsiveness.

Immunological profile of 42 men working under exposure to chlorine for a period from 2 to 38 years was analysed. Toxicological analyses of air samples which were carried out for 20 years showed similar chlorine concentration ranging from 0.21 to 1.05 mg/m3. The number of B, T, and non-B, non-T lymphocytes was determined as well as the C3c, C4 complement components and proteins of acute phase reaction: alpha 1-acid-glycoprotein, haptoglobin and ceruloplasmin in the serum. Chronic exposure to chlorine produced a stimulating effect on the immune system, which was manifested by elevated IgA, IgD and IgM levels, the concentration of acute phase reaction proteins and increased number of B lymphocytes. The observed phenomenon had no influence on the antibacterial and anticancer immunity of the workers.

The porcine complement proteins C3 and C4 have been isolated and then characterized using small-angle scattering methods. Within the limits of experimental errors, the porcine proteins are virtually identical with the corresponding human proteins as measured in terms of mol. wt, Mr and radius of gyration, R,: Mr(C3) = 198,000, Mr(C4) = 207,000, and R(C3) = 4.4 nm, R(C4) = 4.5 nm. The C3 and C4 proteins from pigs show cross-immunity with monoclonal antibodies (mAbs) raised against human C3 and C4, respectively. Using the Fab fragments of these mAbs as markers, it is indicated that porcine C3 and C4 undergo a conformational change after reaction with methylamine. The relatively large increase in the radius of gyration observed, delta R = 1.0-1.2 nm, going from the Fab complexes to the Fab complexes of the methylamine derivatives, is similar to that observed for human C3 under similar conditions. This may indicate that methylamine cleaves a labile thiol ester bond supposed to be present within the porcine proteins and that the epitopes interacting with the Fab fragments are very similar to those of the human proteins. Porcine C3 also resembles the human analogue by forming dimers after being subjected to methylamine and dilute lauryl sulphate: Mr = 404,000 and R = 7.9 nm.

Sodium selenite exerts a marked inhibiting effect on the hemolysis induced by complement fixation. The results of rocket immunoelectrophoresis tests for the activated fragments C3d and C4d show that sodium selenite inhibits complement activation through the alternative pathway.

Drugs which induce systemic lupus erythematosus as a toxic side effect have been shown to inhibit the covalent binding of C4, which is an important event in immune complex clearance in normal individuals. Human C4 is encoded at two polymorphic loci, C4A and C4B within the Major Histocompatibility Complex and patients with idiopathic SLE are more likely to have a non-functional (null) C4A gene. The C4A and C4B gene products differ in reactivity with C4A being more reactive with nitrogen nucleophiles, including hydralazine and isoniazid (drugs which induce SLE), than with oxygen nucleophiles. We have established an assay system which allows the effect of nucleophiles on C4 in animal sera to be investigated. It has been found that in comparing reactivity of guinea-pig C4 with human C4A and human C4B that guinea-pig C4 is like human C4A and shows greater reactivity towards nitrogen nucleophiles than towards oxygen nucleophiles. This suggests that the guinea-pig should be a good animal model for drug-induced SLE.